Door-operating mechanism



June 29 1926.

' J. G. ROBINSON noon OPERATING uscmmsu Filed June 16, 1924 5 Sheets-Sheet 1 June 29 1926. 1,590,443

J. G. ROBINSON DOQR OPERATING mscnmrsm Filed June 16, 192 1 3 Sheets-Sheet 2 June-"29. 192s. v 1,590,443

J. G. ROBlNSON DOOR OPERATING MECHANISM Filed June 16, 1924 3 Sheets-Sheet 3 Patented June 29, 1926.

osirao srsrss PATENEPQEEI-CE.

JAY e. noBnvso-n, or Lcnroneo, iimmois.

DOOR-OPERATING IVIECHKNISM.

Application filed June "16, 1924. Serial No. 720385.

My invention is an improvement in pneumatically-operated doors for locomotive fire boxes, certain features of'the invention being applicable, .however, to doors used for other purposes and to moving :parts other tl an doors. fine of the objects of the in vention is to provide improved means for retarding'the movement of a door near the limits oi its movement, thereby bringing it 'to rest withontshock. Another object when two doors are employed, one moving up- -w ardly fwhen the other moves downwardly, isxto so connect the doors 'loy pivoted-memhere that each substantially counteracts the weight of the other'i-n such manner that the retardation of "each door is communicated :to the other. Another and important object is to produce retardation of the door movement-near the limits-thereo fby the action of l the pivotal members by which the doors are operated and connected, xthns obviating the necessity of relying for the cushioning effect exclusively *upon the com ression of air in the pneumatic operating mechanism. Other objects All appear in the following description of the particular structure in which I have embodied the invention .in the mechanism shown in the accompanying drawings, in which- Figure 1 is a front-elevation ot *a locomotive fire box door embodying any invention with the doors in closed position.

Figure 2 is an end elevation from the l ft-hand side of the structure shown in gure '1.

l igure '3 is an end view from the righthand side'oft he structure shown in Figure '1.

Figure l is a front elevation similar ito Figure 1, but showing the doors in open cl ied'in United States Letters Patent No. '92 80, granted to F. Shoemaker, May 25,

and in my Patents Nos. 1,492,896, I granted Mayo, 1924:, and 1,325,657, granted December 23,1919, respectively. I

The door opening is surrounded and definedby frame l to which the doors 4 and 5 are pivot-ed at 2 and '3, the doors being designed to meet in closed position along a substantially horizontal line wa'hout midway 0f *thedoor open-i'ngmndmo move toward and away r-rom each other in a substantially vertical plane in closing and opening respecti vel-y. The two door operating lovers -'6 and '7 are pivoted to the door frame at #8 and 9 respectively. Links 10 and 11 are pivoted to levers 6 and '7 at 12 and 1'3 :re- :spectively, and at their opposite ends these lin'ks are 'p'iavoted at L4 and 15 to thed'oor-s 4 and "5 respectivel y. The levers and 7 are conneotetl by a link 16. The link 116 is :pivoted to thelever 7 at '18, the lever'iful- 'orum '9 being heta-Ween the pivots '13 and "L8. T-hepivotal connection 17 oi-th'e lirik'lfiwith lever "B is between the fulcrum 8 of that lever and *the pivot '12.

The lever -6 iexztends beyond the pivot 12 as shown at "1 9, the part '19 serving :as an operating handle when the door is operated manually. The lever 7 "has an arm '20 *proj'ecting upwardly and pivoted at' 20 'to the li-nkQl, which at its opposite end is pivoted at 22 lo the piston rod 23 of the pneumatic operatingicylinderwhichisdesi-gnatedgenerally by the numeral 24.

The doors are opened 'and closed *by the Y inward and outward movement of the piston rod 23 operating in the -'cy1intler 24. "The "outward movementioi thepiston rod 23ythat is its movement toward the l'eft as viewed in the drawings, rotates the lever ,7 upon'i'ts pivot 9 in counter-clockwise direction, thus imparting an upward thrust 'to the link l l and upper door 5. The counter-clockwise movement of the lever "7 also imposes a downward thrust upon the' link 16 which in ".tllll'l is transmitted to the lever 6, and through the link 10 to the "lower door 4. "The result, therefore, of "the movement ofthe pistonrod to the leftis to raisethe'npper door 5 and'to lowerthe l'owerdoor 4, thereh y moving them to the open position shown in Figure 4. "Upon the reverse movement of the piston rod 23 toward "the right, as viewed in the drawings, the forees are trans- *mitted in the same way but in the opposite direction, thereby causing the doors to olose. It will be observed thatlhave placed the operating cylinder 24 above the '-door :opening and spaced outwardly sufficiently "from the door frame 1 to permit 'the upper door 5 to pass between it and the :door frame.

The construct-ion :of the cylinder :214 rand its operation are as described in :the :prior patents to Shoemaker and to myself above referred to, and a brief description thereof will suflice for the purposes of this specification. As shown in Figure 5, the cylinder is provided with two auxiliary alined bores and 26 of different diameter, and the piston rod 28 has secured thereto a large piston 27 fitting the larger bore 25, and a smaller piston 28 fitting the smaller bore 26. These pistons are provided with the usual rings 2930, and cup leathers 8132. Fluid under pressure, compressed air being used for the operation of fire-box doors upon locomotives, is supplied through the pipe 85.

Referring now to Figure 5, the pipe is connected by a T-coupling 35 to an opening in the side of the cylinder 24, which opening is the entrance to a duct leading to the end of the large bore 25 immediately adjacent its junction with the small bore 26. This duct extends inwardly, as indicated at 38, thence parallel to the axis of the cylinder as indicated at 89, and thence in the opposite direction parallel to the axis of the cylinder as indicated at 40,'a right angular extension 41 at the inner end of the part 4-0 leading the duct to the larger bore 25 adjacent its junction with the small bore. At the junction of the parts 39 and 40 of this duct, I provide an inwardly opening checkvalve 42, and in the part 41 of the duct adjacent its point of communication with the large bore 25, 1 provide a three-way valve 43. In the position of the valve 43 illustrated in Figure 5, its through bore 44 establishes continuity of the duct and communication between the large bore 25 and the pipe 35. lV hen the valve 43 is rotated ninety degrees clockwise communication is established between the radial bore 45 of the valve and thelarge bore 25 and thence through the bore 44 to the atmosphere at 46.

During the pneumatic operation of the doors, the valve 43 always remains in the position shown in Figure 5, being moved from that position only for a special purpose to be hereinafter described, and the space 25 between the large and small pistons is, therefore, in constant communication through the pipe 35 with the source of air pressure.

The pipe 35 beyond the point 35 where it communicates with the space between the pistons extends over the top of the door opening and down at the side thereof to a valve 86 which may be of the type shown in the Robinson and Shoemaker patents above referred to. As my present invention involves no novelty in the construction of this valve, I will here simply describe the functions which it performs. The valve is operated by a foot-treadle 87. When the treadle is in its normal position, i. e., its elevated position, the valve closes the portin the valve casing with which pipe 35 communicates and prevents the flow of air from pipe 35 to pipe 34, pipe 34 in this position of the treadle and valve being in communication with the atmosphere through an exhaust opening in the valve casing. When the valve is moved by depressing the treadle the pipe 34 is cut off from the exhaust opening and placed in communication with the pipe 85 permitting the How of air from pipe'85 through pipe to the outer side of the large piston through the duct 46 shown in Figure The duct 46 is provided with two branches and 61. The branch 60 communicates with the cylinder through its side wall at a point adjacent the outer or right-hand end thereof as viewed in Figure 5, and the branch 61 communicates with the cylinder through its end wall. In the branch 61, I provide an inwardly opening check-valve 47 which is by-passed by a minute bleed opening 48, which bleed opening 1 have shown as extending directly through the body of the valve 47. In operation, assuming that the doors are closed and the pistons 27, 28, at their extreme right-hand position as viewed in Figure 5, depression of the treadle 87 establishes communication between the air supply pipe 35 and the pipe 34, thereby admitting pressure through the duct 46 and branch 61 to the outer side of the large piston 27. The space between the pistons 27 and 28 is constantly in communication with the source of compressed air through the pipe 35 as above explained, this constant pressure of air between the large and small pistons never being interrupted during the pneumatic operation of the doors. l/Vhen pressure is admitted on the outer side of the large piston 27 by depression of the treadle above described the two pistons with the piston rod 23 to which they are connected move to the left. This movement is due to the fact that the pressure of air upon the small piston 28 and upon the outer side of the large piston 27 overcomes the pressure acting in the opposite direction upon the inner side of the piston 27, it being understood that the space upon the outer side 49 of the small piston is in communication with the atmosphere. In the conditions described, therefore, the air pressure acting to move the pistons to the left is effective upon a greater area, namely the area of one side of the large piston plus one side of the small piston, while the pressure acting to move the pistons to the right is effective only upon one side of the large piston. The effective effort of the air pres sure, therefore, is that due to the area of one side of the small piston. As the pistons move to the left the check-valve S9 prevents escape of air from the space between the pistons, and as this body of air is moved by the movement of the pistons from the ill) nae-ones l'arge bore 25 to the small bore 26'', it is.

= tained is dependent upon the air between the two pistons being confinedin' that space, but in practice diiiiculty is sometimes experienced in maintaining the cup leathers 31 32, and rings 29, 30, in suiiiciently perfect condition to confine the body oiair between the pistons to an entent'su iiicient to produce a. perfect cushioning effect. To improve this cushioning eii ect is one of the objects of the invention claimed herein, the opera tion above described being that which has. previously been in use as described in the. prior patents hereinbefore referred to.

Upon reference to Figure 1', it will be observed that the links 10, ll, extend approximately at right angles to the levers, 6, 7, when the doors are in closed position, and by reference to Figure 4, it will be" observed that during the opening movement of the doors the links rotate, the link 11 counterclockwise and the link 10 clockwise, upon their pivotal connections 13' and 12 withthe levers 7 and 6, respectively. hen the doors have reached their fully open position the link 11 has rotated almost into alinement with the lever 7 and the link 10 has rotated into alinement with the lever 6. In Figure 6, I have shown the movement of the levers and links plotted in closed" intermediate and: open position. The line w represents the meeting edges of the doors when in closed position; the lines a, 64 represent the edges of the lower and upper doors respectively when in intermediate position; and the lines 6, I) represent the edges of the upper and lower doors respectively when in extreme open position. I have applied numerals 10: and 11 to the links in this view and the numerals 6" and 7 to the levers, and have added to these numerals the letter a to designate their intermediate positions and the letter Z) to designate their poistion when the doors are open to their full extent. connecting the lever 7 with the link 11, I have designated by the letter 0, and the corresponding arc of movement of the pivotal connection between the lever 6 and the link 10-, I have designated by the letter d. The arcuate movement of the pivotal connection of the link 11 with the upper t will be observed,.

The arc of movement of the pivot door, I have designated 6, and the arc of movement of the pivotal connection between the link 10 and the lower door I have designated The pivotal connection of the doors. with the door frame isindicated by the numerals 2, 31 Upon reference to the lower part or the diagram showing themovernent of the lever and link connected" to the lower door, it will be observed that duri'ng'the: first part of the opening movement of thevd oor, the pathsof'movement of the pivotal conections at opposite endsof the link 10 converge, then intersect, and after their intersection, diverge. The proportions of" the lever 6 and link 10 ares-och and the points of pivotal connection of the link 10 with the'lever' and with the door are so related that when the lower door has reached its fully open position the linklOis in alinement with the lever 6, this latter position of these parts being indicated by the reference numerals 6 and 10 I have shown the position 10 of the link 10 at a slight angle to the lever 6 in order to make the illustration clear, but in practice and as actually constructedthe link 10 falls into substantial alinement with the link 6 in the fully open position of the door. It will also be observed that as the lever 6 moves from the position designated 6 through the position 6 to the position 6 the force transmitted from the lever through the link 10 to the door becomes less and less etl'ective by reason of the rotation of the link from a position substantially normal to the lever to a position in alinement therewith, and it will further be apparent that the movement of the door cannot proceed beyond the position indicated. by the numerals 6 and 10". At this point the arcs cl and 7 have diverged to an extent equal to the length of the link 10, and as continued movement could take place only by further divergence of these arcs which is prevented by the link 10' the doors are brought to a stop in the. position corresponding to that indicated by the numerals 6 and 10 means I have provided for the gradual retard'ation andv stopping of the door move- By this 1 llO ment', and have provided a cushioning ellect 7 that brings the door to rest without shock, and the means so provided are independent of the cushioning effect. taking place by reason of compression of the air confined between the two pistons as above described. The gradual decrease in effectiveness of the force transmitted from the lever 6 through the link 10 to the door causes a diminution of the resultant force acting upon the door as it approaches the limit of its opening movement and hence the absolute arrest of the opening movement by the arrival of the parts at the position indicated by the numerals 6 and 10 is accomplished without shock.

A further advantage of the construction and operation last above described arises from the fact that any tendency of the lower door to rebound after arriving at its fully open position, is prevented not only by the weight of the lower door, but by the fact that any upward movement of the lower door at this time could take place only by causing a continued clockwise rotation of the lever 6 caused by continued clockwise rotation of the link 10, and such clockwise movement of the lever 6 is resisted by the downward pull thereby caused upon the link 16, which downward pull is opposed by the weight of the upper door.

The action above described in connection with the lower door also takes place in connection with the upper door, though to a lesser extent, as it will be observed from Figure l, that in the extreme open position of the doors the link 11 is not in exact alinement with the lever 7. I found that sufficient cushioning effect is produced by so proportioning and arranging the parts connected to the lower door that the link 10 comes into alinement with the lever 6 when the doors are fully opened, and, of course, the cushioning effect applied to the lower door is transmit-ted to the upper door by reason of their interconnection between the levers and link.

It will be observed that the interconnection between the upper and lower doors is such that the weight of each door exerts an upward force upon the other door, thereby causing the doors to balance each other with the result that when left free to move under the force of gravity they will remain stationary in any position to which they are adjusted. In operation it sometimes becomes desirable to open the doors partway and to leave them in that position for a considerable time, as when a train is approaching a station and it is desired to abate the smoke. The means provided for this purpose are described and claimed in the Bobinson Patent No. 1392,896 above referred to, and I shall, therefore, herein introduce only a brief description thereof. Assuming that the doors are in the closed position shown in Figure 1, and it is desired to open them a short distance and to leave them in that position for some time, it simply is necessary to turn the valve 43, shown in Figure 5, a quarter turn clockwise thereby shutting off the supply of pressure to the space between the two pistons and establishing communication between that space and the atmosphere. The doors are thereby released from any force due to air pressure, the air between the pistons having been allowed to escape and the air on the outer side of the large piston being shut off by reason of the operating treadle being in its upper, normal, position.

By reference to Figures 1, 2 and'3, it will be observed that I have provided an operating handle attached to the upper door above its hinge pivot 3. With the valve 43 adjusted as above described, the doors may be opened by manual operation of the lever 50 and the doors will remain in any position to which they are adjusted by reason of the fact that they are so connected as to counter-balance each other and are not subject to air pressure.

\Vhile I have shown an inwardly opening check valve in the duct 3839-40l1 lead ing from the compressed air pi 3e 35 to the space between the two pistons, have found that the use of this check valve may be dispensed with, ample cushioning effect upon the opening of the doors being obtained by the action of the levers and links above described. VVhen the check valve is used, its effect is to confine the body of air between the two pistons, thereby causing this air to be subjected to pressure above that of the air supply when the pistons move to the left, to the position corresponding to the open posi tion of the doors. When the check valve is removed, the space between the pistons is never subjected to air pressure above that of the main air supply except to the extent caused by the size of the duct 38394E0 ll not permitting the backward flow of air toward the pipe 35 with suflicient rapidity to prevent some building up of pressure between the pistons when they move to the left. As above stated, I have found that sufiicient cushioning effect may be obtained without the use of the check valve.

The doors will remain open as long as the treadle 37 is held depressed, thereby maintaining air pressure between the pistons and upon the outer side of the large piston. When the foot treadle is released and returns to its normally elevated position, commimication is thereby established between the pipe 3-1: and atmosphere through the valve 36.

I effect the cushioning upon the closing of the doors in the manner described in the patents before referred to. Upon reference to Figure 5 it will be apparent that upon the movement of the piston 27 to the right, which is its movement in closing the doors, the air at the right-hand end of bore 25 at first escapes through branch 60 of duct 46 but that when piston 27 arrives opposite and obstructs branch 60 the remaining air in the. end of the cylinder is entrapped and can escape only through the minute bleed opening 48 with the result that this entrapped air is compressed before it can escape thus cushioning the closing movement of the door.

Vhat I claim as my invention is:

1. In a structure of the class described, a door supported on a pivot to move in the plane of a door opening, a: lever fulerumed eccentrically of said door, a link, pivots con necting said link to said lever and door, the opening movement of said door being lim-- ited by the divergence of the arcuate paths of the pivots at the opposite ends. of said link to an extent greater than the length of said link, and saidlink in the extreme open position of, said door lying in alinement with said lever and extending from its pivotal connection with said. lever toward the fulcrum of said lever.

2. In a structure of the class described, two doors movable toward and away "from each other in a substantially vertical plane, door connecting members having pivotal connection withsaidv doors, said connecting members causing the weight of each door to QZZGI'tan upwardly acting force on the other door, said connecting members comprising levers and links, each of said links having pivotal connection with one of said levers and with one of said doors, the opening movement of said doors being limited-by the divergence of the paths of movement of the pivots at opposite ends of one of said links to an extent greater than the length of said link.

3. In a structure of the class described, two doors movable toward and away from each other in a substantially vertical plane, door connecting members having pivotal connection with said doors, said connecting members causing the weight of each door to exert an upwardly acting force on the other door, said connecting members comprising levers and links, each of said links having pivotal connection with one of said levers and with one of said doors, the opening movement of said doors being limited by the divergence of the paths of movement of the pivots at opposite ends of one of said links to an extent greater than the length of said link, and means for applying power to said doors through said levers to open and close the same.

4. In a structure of the class described, two doors pivoted for movement toward and away from each other in a substantially vertical plane, door connecting members having pivotal connection with said doors, said connecting members causing the weight of each door to exert an upwardly acting force on the other door, said connecting members comprising levers and links, each of said links having pivotal connection with one of said levers and with one of said doors, the opening movement of said doorsbeing limited by the divergence of the arcs of movement of the pivots at opposite ends of one of said links to an extent greater than the length of said link.

5. In a structure of the class described, two doors pivoted for movement toward and away from each other in a substantially verto said doors through said levers to open and close the same.

6'. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane or adoor opening and adapted to meet substantially midway of said opening, two levers having fixed fulcra, links each having pivotal connection atone end with one of said levers and at the opposite ends with said upper and lower doors respectively, said levers in the closed position of said doors lying between the meeting edges oi said doors and the pivotal connections of said links with the doors, and a link having pivotal connection with said levers upon opposite sides of their fulcra.

7. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane of a door opening and adapted to meet substantially midway of said opening, two levers having fixed fulcra, links each having pivotal connection at one end with one of said levers and at the opposite end with said upper and lower doors respectively, said links in the closed position of said doors lying substantially normal to said levers.

8. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane of a door opening and adapted to meet substantially midway of said opening, two levers having fixed fulcra, links each having pivotal connection at one end with one of said levers and at the opposite ends with said upper and lower doors respectively, said links in the closed position of said doors lying subtantially normal to said levers, said levers in the closed position of said doors lying between the meeting edges of said doors and the pivotal connection of said links with the doors, and a link having pivotal connection with said levers upon opposite sides of their fulcra.

9. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane of a door opening and adapted to meet on a substantially horizontal line substantially midway of said opening, two levers having fixed fulcra, links each having pivotal connection at one end with one of said levers and at the opposite ends with said upper and lower doors respectively, said levers in the closed position of said doors lying between the meeting edges of said doors and the pivotal connections of said links with the doors, a link having pivotal connection with said levers upon opposite sides o'l their fulora, a fluidoperated cylinder above said door opening and having its axis substantially horizontal, and a piston in said cylinder, said piston being linked to said levers.

10. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane of a door opening and adapted to meet on a substantially horizontal line substantially midway of said opening, two levers having fixed fulora, links each having pivotal connection at one end with one of said levers and at the opposite ends with said upper and lower doors respectively, said links in the closed position of said doors lying substantially normal to said levers, a link having pivotal connection with said levers on opposite sides of their fulcra, a fluid operated cylinder above said door opening and having its axis substantially horizontal, and a piston in said cylinder, saidpiston being linked to said levers.

11. In a device of the class described, an upper and a lower door pivoted for movement parallel to the plane of a door opening and adapted to meet on a substantially horizontal line substantially midway of said opening, two levers having fixed fulcra, links each having pivotal connection at one end with one of said levers and at the opposite ends with said upper and lower doors respectively, said links in the closed position of said doors lying substantially normal to said levers, said levers in the closed position of said doors lying between the meeting edges of said doors and the pivotal connection of said links with the doors, a link having pivotal connection with said levers upon opposite sides of their fulcra, a fluid-operated cylinder above said door opening and having its axis substantially horizontal, and a piston in said cylinder, said piston being linked to said levers.

Signed at Chicago, Illinois, this 9th day of June, 1924.

JAY G. ROBINSON. 

